cant open Epub book on Kobo Aura

New Problem with downloading Epub book from Overdrive Public Library Account

Everything was working fine with ADE 4.5, then out of the blue after downloading a book from Library,   I get the   the standard "oops this document couldn't be opened .....protected by DRM''''etc"  (the book had NOT expired).

In Adobe I have:

Deauthorized then reauthorized the device and my computer

On Kobo I have

Done a factory restart on my Kobo through 'settings' - went through the  setup again - language etc, however I did not loose my current Kobo book on my ereader, so not sure if this really was a factory reset)

Any other suggestions would be really appreciated!